Project: Ghana Emergency Medicine Collaborative Document Title: Systematic Evaluation to Non-Traumatic Head CTs Author(s) Rashmi U. Kothari, MD (KCMS/MSU), 2012 License: Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: We have reviewed this material in accordance with U.S. Copyright Law and have tried to maximize your ability to use, share, and adapt it. These lectures have been modified in the process of making a publicly shareable version. The citation key on the following slide provides information about how you may share and adapt this material. Copyright holders of content included in this material should contact with any questions, corrections, or clarification regarding the use of content. For more information about how to cite these materials visit Any medical information in this material is intended to inform and educate and is not a tool for self- diagnosis or a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional. Please speak to your physician if you have questions about your medical condition. Viewer discretion is advised: Some medical content is graphic and may not be suitable for all viewers. 1

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Systematic Evaluation to Non-Traumatic Head CTs Rashmi U. Kothari, MD KCMS/MSU Source Undetermined

Why do you need to be able to evaluate a CT  Radiology report is not immediately available  Need immediate intervention  Don’t trust anyone

Course Outline  Basic principles of CT  Basic anatomy  Systematic approach  CT Potpourri

Course Goals  Learn “Blood Can Be Very Bad” approach to reading CTs  Identify classic CT findings

Disclaimer  Make you a neuroradiologist  Teach you cause of finding of abnormality  Help you with contrast CTs

Basic Principles of CT Imaging Source Undetermined

X-rays Absorbed Differently by Different Tissues Radiodense Bone Metal Calcium Blood Grey matter Radiolucent Air Spinal fluid Ischemic infarct Edema White matter Source Undetermined

Attenuation (amount of radiation blocked by tissue) Air Blood Bone HU HU HU=Hounsfield Units HU

Windowing  Blood Brain Blood Bone Source Undetermined

CT Anatomy  Six levels of cuts  Cortical sulci  Lateral Ventricles  Basal Ganglia  3 rd Ventricle  Midbrain  Pons Source Undetermined

CT Anatomy: Cortical Sulci & Lat. Ventricle Falx Cortical sulci Frontal lobe Parietal lobe Lateral ventricles Occipital lobe Source Undetermined

CT Anatomy: Basal Ganglia & 3 rd Ventricle Anterior horns Insular ribbon Sylvian fissure 3 rd ventricle Quadrigeminal cistern Anterior horns Choroid plexus. Source Undetermined

CT Anatomy: Midbrain & Pons Frontal sinus Suprastellar cistern Pons 4 th ventrical Sylvian fissure Insular ribbon Ambient cistern (cirummesenphalic cistern) Source Undetermined

Systematic Approach to Head CTs  Perron et al: Carolina’s Medical Center  “Blood Can Be Very Bad” pnemonic  Course reviewing 12 scans & short histories  Pre-test 60% to Post-test 78%  _peds/perron_ich _acep_2005_peds_ course.pdf

“Blood Can Be Very Bad”  Blood  Cisterns  Brain  Ventricles  Bone Perron et al: Ann Emerg Med 1998:32:

“Blood Can Be Very Bad”  Acute blood = hyperdense (white)  HU  As it ages it becomes hypodense  At 1-2 weeks it is isodense with brain

“Blood Can Be Very Bad” Source Undetermined

“Blood Can Be Very Bad”  4 cisterns:  Suprasellar  Quadrigeminal  Slyvian  Ambient Source Undetermined

Andrew D. Perron, MD, FACEP 21 Cisterns: Is there blood? Are they open? Source Undetermined

“Blood Can Be Very Bad” Brain Source Undetermined

“Blood Can Be Very Bad” Ventricle Source Undetermined

Andrew D. Perron, MD, FACEP “Blood Can Be Very Bad” Bone Source Undetermined

Classic CT Findings Source Undetermined

Subdural Concave shape Venous bleeds Crosses suture line Epidural Lens shape 85% arterial bleeds Middle meningeal art Lucid period Source Undetermined

Intracerebral Hemorrhage  10% of all strokes  2 major causes  Hypertension  Blacks & Asians  50% basal ganglia  Pons  Cerebellum  Amyloid  Caucasians  Lobar  Recurrent Source Undetermined

Subarachnoid Hemorrhage  5-10% of all strokes  Aneurysms, AVMs, trauma  Hyperdense, fuzzy  Locations of blood C- –Sulci –Sylvian fissure –Circle of Willis –Falx –Tentorium Source Undetermined

ICHNormalICH SAHSAHSAH Source Undetermined

Findings Suggestive of ICH  Normal Calcification  Basal ganglia  Choroid plexus  Pineal gland C- Source Undetermined

Findings Suggestive of ICH  Metal  Very hypodense  “Sparks”  Clips, bullets, metallic catheters C- Source Undetermined

Findings Suggestive of ICH C- ? Source Undetermined

Volume Averaging (Technical Issues Mimicking ICH)  Orbital roof  Petrous portion of temporal bone  Pituitary fossa  Brainstem Source Undetermined

Findings Suggestive of ICH/SAH ? ? C- Source Undetermined

Motion Artifact (Technical Issues Mimicking ICH or SAH)  Streaky  Hyperdense  Boney prominence Source Undetermined

Evolution of an Infarct Ultra-Acute 0-3 hours Acute-Subacute 6hrs-days Chronic 1 year Source Undetermined

Ultra-Early CT Findings  Normal  Sulcal effacement  Loss of insular ribbon  Loss of grey-white interface  Acute hypodensity Source Undetermined

Sulcal Effacement Source Undetermined

Loss of Insular Ribbon Source Undetermined

Loss of Sulci & Acute Hypodensity Source Undetermined

Acute Hypodensity Source Undetermined

Acute-Subacute Stroke (hours-days)  Hypodense  Well demarcated  Mass effect  Midline shift  Loss of sulci Source Undetermined

Old Infarct (months to years)  Density of CSF  Well demarcated  Ventrical enlargement  Sulci enlargement  No sulcal effacement  No mass effect Source Undetermined

Suggestive of an Infarct? Source Undetermined

Suggestive of an Infarct? Tumor Stroke Source Undetermined

Case Presentations

Thalamic ICH Source Undetermined

Normal Source Undetermined

Chronic Frontal Subdural Source Undetermined

Subacute Right Parietal Infarct Source Undetermined

continued Source Undetermined

SAHNormal Source Undetermined

Acute Subdural Source Undetermined

Normal Source Undetermined

Closed Ventricles Source Undetermined

Andrew D. Perron, MD, FACEP Cisterns: Are they open? Source Undetermined

Metallic Artifact Source Undetermined

Brainstem SAH Source Undetermined

Chronic MCA Infarct Source Undetermined

Left IVH Source Undetermined

Epidural Source Undetermined

Rt Subacute Epidural Source Undetermined

Sagital Sinus Source Undetermined

Subacute Infarct Source Undetermined

Renal Cell Metastasis Source Undetermined

continued Source Undetermined

SAH Normal Source Undetermined

48 hr old Right Temporal Infarct Source Undetermined

Acute on Chronic Subdural Source Undetermined

SAH Source Undetermined

Rt Parietal Fx with Air Source Undetermined

Brain Abscess Source Undetermined

Calcification Basal Ganglia Source Undetermined

continued Source Undetermined

hours 3-4 days 7-10 days months Source Undetermined

Trauma with Air Source Undetermined

Dense MCA Sign Source Undetermined

Subacute Brainstem Infarct Source Undetermined

Atrophy Source Undetermined

Trauma with SAH Source Undetermined

Bitemporal Edema (Herpes) Source Undetermined

Meningioma Source Undetermined

Caudate Infarct Source Undetermined

IVH Left Lateral Horn Source Undetermined

Ultra-Early Right Parietal Infarct Right Sulcal Effacement Source Undetermined

Continued Source Undetermined

Subacute Infarct (Rt Temporal Lobe) Source Undetermined

Periventricular White Matter Disease Source Undetermined

Chronic Rt Occipital Infarct Source Undetermined

Subacute Subdural Source Undetermined

Traumatic Petechae Source Undetermined

Loss of Sulci & Sylvian Fissure Source Undetermined

Old Lt Lacunar Infarct Source Undetermined

Subacute Lt Subdural Source Undetermined

Rt MCA Infarct with Hemorrhage Source Undetermined

Lt Sagital Vein Thrombosis Source Undetermined

SAH with Blood along Falx & in Ventricle Source Undetermined

Tumor Source Undetermined

Tumor Source Undetermined

CT Ground Rule Radiodense Bone Blood Calcium Grey matter Metal Radiolucent Spinal fluid Ischemic infarct Edema White matter Air Source Undetermined

“Blood Can Be Very Bad”  Blood  Cisterns  Brain  Ventricles  Bone Perron et al: Ann Emerg Med 1998:32:

Intracerebral Hemorrhage  Appearance  Hyperdense  Well demarcated  Globular  Location  Intraparenchyma l  Mimics  Normal Calcification  Basal ganglia  Choroid plexus  Pineal gland  Artifacts  Metal  Catheters  Volume Averaging  Motion Source Undetermined

Subarachnoid Hemorrhage  Appearance  Hyperdense  Fuzzy  Locations of blood  Sulci  Sylvian fissure  Circle of Willis  Falx  Tentorium  Mimics  Contrast  Calcified Falx  Normal Tentorium  Motion artifact Source Undetermined

Ultra-Early Infarct Normal Sulcal effacement Loss of insular ribbon Loss of grey-white interface Acute hypodensity Acute-Subacute Hypodense Well demarcated Mass effect Midline shift Loss of sulci Old Infarcts Density of CSF Well demarcated Ventrical enlargement Sulci enlargement No sulcal effacement No mass effect Source Undetermined